Accounting · 20 October 2026 · 5 min read
In Australia, most GST on a sale starts at the till. If the tax code is wrong at the point of sale, it is wrong in your BAS. This is how the numbers should flow.
It starts with the tax code on the product
Each product needs the correct tax treatment: taxable at 10%, GST-free, or input-taxed. When the product is sold, the system records the sale amount and the GST on it. Mistakes here repeat on every sale of that product.
From sale to ledger
- The sale posts income to the right account and GST collected to the GST liability account.
- Purchases post GST paid to the GST receivable (input tax credit) account.
- Returns and voids reverse the same amounts, so the BAS reflects what actually stood.
What to check each period
- GST-free and taxable sales are both showing in the right BAS labels.
- Refunds and credit notes have reduced GST on sales for the right period.
- Payments and receipts match the bank before you lodge.
Why one system helps
When the till and the ledger are the same system, the BAS summary is built from the same transactions your staff rang up. There is no export, so there is no export to get wrong.
This article is general information and not tax advice. Confirm treatment for your business with your accountant. See NiyuSuite Accounting for how GST and BAS reporting works.